2001 A6 Trailer Hitch Wiring
 

Hey all:

Ok, I've got one I'm confused about. I have an '01 2.7T with the factory trailer hitch installed. I finally got around to getting a tongue and ball for it, but when I went hunting around to find where the wriring hookup was, I couldn't find anyting! So, I went to the local trailer supply house to pick up a 4-pin pigtail, and was going to tie it into the passenger side brake light. The guy behind the counter informed me that "You really don't want to do that", and mentioned something about some kind of adapter module so I don't confused the hell out of the car's computer. I shrugged, said thanks, and walked out.

So, my quesitons:
1) Did Audi actually install the trailer hitch option without putting wiring in for the brake lights, or am I just missing where they have it hidden?

2) Was the guy at the supply store right? Is there something special that needs to be purchased to make this work?

Thanks all!
-Chris

RE: 2001 A6 Trailer Hitch Wiring
 

This post is from another audi site. This is for an Aufi 5000 but it should be similar. Good luck

OK... after a few false starts due to being partly blind these days... here's the I connected the trailer lights as best as I could figure it out.

The flat 4-pin harness connecting to the car uses the following...

(W)hite - Ground
(B)rown - Marker Lights
(G)reen - Right turn and brake
(Y)ellow - Left turn and brake

Since connecting the brakes to the left and right turn would end up with all the lights going every time the lights are activated I opted to use the Brown for brake lights.

Left turn for the audi is BK/W and is connected to the Y at the left rear corner where the harness breaks out for left and right. I stripped off a section of the insulation on the BK/W leaving the copper intact and then soldering the yellow to that.

Peeling back the sheath for the right wires a little at the break out point reveals more space to work on the BK/G wire for the right turn. I used the same method to solder this wire. It also helps to unfasten the ground point for more slack.

I soldered a ring to the White ground wire for connection to the common ground point when the bolt would be replaced later.

To avoid the light out warning I spliced into the rear brake light at the rear light controller booster connector. The Black connector is the input to this unit. The R/BK wire comes from the brake switch. It gets jumpered across to a second input. This is presumably to drive the left and right sides seperately. I connected a length of wire to extend this to the rear corner where the rest of the lights were being connected. I connected this last wire to the remaining Brown wire of the trailer harness.

There are no bulb out warnings but there are also no side marker lights for night time driving.

I might try and use a diode to connect the brake lights and resolve this issue of all the lights all the time.

But... so far so good for day time driving... more to come whjen I am done trying the diode solution.

RE: 2001 A6 Trailer Hitch Wiring
 

Much appreciated, Envied.
That was the sort of information I was looking for. Strange about the marker lights though.......I might have to scratch my head a little more on why they'd die in the process.

-Red.

OK, this seems ton answer my questions, i guess... I have a 1997 A6 Avant quattro and had a hitch made for the car, and am in the process of hooking up the light wiring, so I am worried about the extra lights screwing up the electronics...

This is basically the 5000/100 platform and wiring so i'm guessing the normal little black trailer box will do? It seems to work other than the fact i blew the fuse for the parking lights...

Does anyone know if it is ok to use an over the shelf trailer wiring kit for these models?

Circuit Protected Taillight Converter with 4-Pole Hardwire Kit (Includes Testers) Tow Ready Wiring 118175KIT

This is what I used it was easy to install by the directions and worked fine

Ok so i hooked everything up as if it was a normal car (one that doesn't have the bulb check computer) and it didn't affect anything and works great but will switch the trailer lights to LEDs to reduce strain on the system.

The fun part of the installation in the 97 A6 avant was that the bulb-holders have tabs sticking out the bottom that accept standard wire clips so no splicing wires! I just crimped the clips onto the wires going to the trailer wiring harness and plugged them into the bulb-holders and used a bolt on the chassis for the ground, a very simple hookup! What was also great is that i didn't have to take the car apart at all, just opened up the access panel for the 6-disk CD changer.

I'll probably post a photo if anybody else wants to see the result.

quattro4ks - realize this is an old thread, but wondered if you ever took any pics to post uP?